Ski boot

ABSTRACT

A ski boot comprising a rigid shell made of plastic or composite material, which is shaped so as to accommodate the foot of the user, and at least a first and a second removable front sole which, alternatively to each other, are adapted to be fixed in a rigid and stable although easily removable manner to the lower wall of the shell substantially at the tarsal-phalangeal area of the foot; the shell being provided with a first transversal stiffening plate made of metal material which is embedded within the lower wall of the shell, close to the tip of the shell, and is structured/shaped so as to partially emerge/crop out on the outer surface of the lower wall of the shell substantially at the metatarsal-phalangeal area of the foot; the first and second removable front soles comprising: an upper plate-shaped socle which has the upper face shaped so as to be removably coupled to the lower wall of the shell substantially at the tarsal-phalangeal area of the foot, and a second transversal stiffening plate made of metal material which, in turn, is embedded within the upper plate-shaped socle close to the front end of the socle, so as to be aligned below the transversal stiffening plate of the shell, and is further shaped so as to emerge/crop out on the surface of the upper face of the socle substantially at the metatarsal-phalangeal area of the foot, so as to rest directly on the transversal stiffening plate of the shell.

TECHNICAL FIELD

The present invention relates to a ski boot.

More in details, the present invention relates to a multi-purpose ski boot, which may be used for mountaineering and for downhill skiing.

BACKGROUND ART

As is known, downhill skiing and mountaineering are highly specialized sports, which require the use of specific equipment that cannot be used in other contexts without putting one's safety at serious risk. Ski boots are certainly included among the specific equipment for each sport.

Indeed it is known that although the ski boots in both sports have a very similar basic structure, they significantly differ in the lower part of the boot, which is traditionally intended to be fixed to the back of the ski by means of specific ski-binding devices for each sport.

More in detail, the ski boots in both sports essentially consist of a rigid shell made of plastic or composite material, which is shaped so as to accommodate the foot of the skier and has its lower part specifically structured to be fixed to the back of the ski by means of specific ski-binding devices; of a rigid cuff made of plastic or composite material, which is shaped so as to embrace the lower section of the skier's leg from behind and is hinged to the upper part of the shell so as to rotate/swing about a transversal reference axis, which is locally substantially coincident with the articulation axis of the ankle; of an inner liner made of soft and thermal insulating material, which is removably inserted into the shell and cuff, and is shaped so as to envelop and protect both the foot and the lower section of the skier's leg; and lastly of a series of manually-operated closing buckles, which are conveniently distributed on the shell and cuff, and are structured so as to selectively close/tighten the shell and cuff so as to stably immobilize the skier's leg inside the liner.

Obviously, considering that the movements the skier should be able to carry out on the skies significantly vary from one sport to the other and that the ski-binding device should solely accompany these movements, the structure of the ski-binding device substantially varies from one sport to the other. This implies that the shape of the lower part of the shell changes radically depending on whether or not the ski boot is intended for mountaineering or for downhill skiing.

More in detail, the shell of the ski boot is equipped at the bottom with a front sole and with a back heel, which are specifically structured/shaped to be coupled to, respectively, a toe-piece and a heel-piece which are integral with the back of the ski, and are specifically structured to allow the skier to carry out movements which are typical in downhill skiing or movements which are typical in mountaineering.

Obviously, the dimensional specifications of the sole and heel of the ski boot are regulated by two separate international sets of incompatible standards, one which is binding for downhill ski boots (in this case standard ISO 5355) and the other which is binding for mountaineering ski boots (in this case standard ISO 9523 and the dimensional specifications required for coupling to Dynafit mountaineering ski-binding devices or the like).

With the intent to make one same ski boot compatible both with ski-binding devices for downhill skiing and ski-binding devices for mountaineering, certain ski boot manufacturers have developed and marketed ski boots in which the front sole and back heel are removably fixed to the lower part of the shell by means of a series of locking screws. This contrivance allows equipping the boot with two separate front sole and back heel sets, which can be alternatively positioned on the lower part of the shell depending on the skier's needs.

The first front sole and back heel set is specifically structured/dimensioned to meet international standard ISO 5355, which is binding for downhill ski boots, while the second front sole and back heel set is specifically structured/dimensioned to meet international standard ISO 9523, which is binding for mountaineering ski boots, and more particularly, the dimensional specifications required for coupling to Dynafit mountaineering ski-binding devices or the like. Mountaineering ski-binding devices are briefly described for example in European Patent EP-0199098.

A ski boot equipped with two separate removable front sole and back heel sets is described in application PCT WO2009/003904.

Unfortunately, the use of these types of ski boots has underlined certain criticalities, which have strongly penalized their distribution on the market. According to more careful, expert skiers, the above-described ski boot is indeed not capable of providing the user with the same dynamic behaviour and reactivity as a regular ski boot with a sole and heel made in a single piece with the shell, with all the problems this involves.

DISCLOSURE OF INVENTION

Aim of the present invention is to produce a ski boot which is compatible with downhill ski-binding devices and with mountaineering ski-binding devices, and which is capable of providing the skier with the same dynamic behaviour as that of a traditional ski boot with sole and heel made in a single piece with the shell.

In compliance with the above aims, according to the present invention there is provided a ski boot as defined in claim 1, and preferably, though not necessarily, in any one of the claims dependent thereon.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be described with reference to the accompanying drawings, which illustrate a non-limiting embodiment thereof, in which:

FIG. 1 shows a side view of a mountaineering ski boot realized according to the teachings of the present invention, in a first operating configuration and with the lower part sectioned along the centre plane;

FIG. 2 shows a section view of the ski boot shown in FIG. 1, according to the sectional line D-D;

FIG. 3 shows a partly exploded view on enlarged scale of the lower part of the ski boot shown in FIG. 1;

FIG. 4 shows an enlarged and partly exploded view of the lower part of the ski boot shown in FIG. 1, in a second operating configuration;

FIG. 5 shows a section view of the ski boot shown in FIG. 4, according to the same sectional line used in FIG. 2.

BEST MODE FOR CARRYING OUT THE INVENTION

With reference to FIGS. 1, 2 and 3, number 1 indicates as a whole a ski boot structured to be coupled both to a specific ski-binding device for downhill skiing and to a ski-binding device for mountaineering.

Ski boot 1 essentially consists of a rigid outer shell 2 made of plastic or composite material, which is shaped so as to accommodate the whole foot of the user; of a removable front sole 3, which is fixed in a rigid and stable although easily removable manner, to the lower wall 2 a of shell 2, more or less at the tarsal-phalangeal area of the foot, and which cantilevered juts out beyond the ogival tip of shell 2; of a removable back heel 4 which is fixed in a rigid and stable although easily removable manner to the lower wall 2 a of shell 2, at the heel of the foot; and of a rigid cuff 5 made of plastic or composite material, which is preferably substantially C-shaped so as to embrace the lower section of the user's leg from behind, and is hinged to the upper part of shell 2 so as to freely swing about a transversal reference axis A which is locally substantially perpendicular to the vertical centre plane M of the ski boot (that is perpendicular to the plane of the sheet in FIG. 1), and is also locally substantially coincident with the articulation axis of the user's ankle.

More in detail, cuff 5 is freely rotationally fixed to shell 2 by means of two connecting hinges 6 which are arranged on the external and internal lateral sides of shell 2 and cuff 5, aligned along axis A, so as to allow cuff 5 to freely swing on shell 2 while always remaining on a reference plane which is orthogonal to axis A and substantially coincident with the centre plane M of the boot.

In the example shown, in particular, shell 2 and cuff 5 are preferably, though not necessarily, made of nylon (polyamide), PEBAX (polyester-amide) or similar plastic polymers.

With reference to FIGS. 4 and 5, ski boot 1 preferably also comprises a second removable front sole 3′ which is adapted to be fixed in a rigid and stable although easily removable manner to the lower wall 2 a of shell 2, in place of the removable front sole 3, i.e. more or less at the tarsal-phalangeal area of the foot; and a second removable back heel 4′ which is fixed in a rigid and stable although easily removable manner to the lower wall 2 a of shell 2, in place of the removable back heel 4, i.e. at the heel of the foot.

Similarly to the removable front sole 3, also the second removable front sole 3′ cantilevered juts out beyond the ogival tip of shell 2.

With reference to FIG. 1, ski boot 1 is also equipped with an inner liner 7 which is preferably made of soft, thermal insulating material, is housed inside shell 2 and cuff 5 preferably, though not necessarily, in a removable manner, and lastly is shaped so as to embrace and protect the foot and the lower section of the user's leg; and optionally also with a protective, oblong-shaped tongue 8 which is preferably, though not necessarily, made of plastic or composite material, and is arranged resting on shell 2 in the area above the instep of the foot and the lower section of the leg, to cover a longitudinal gap (not shown) which extends along the upper part of shell 2, while remaining locally substantially coplanar to the centre plane M of the boot. This longitudinal gap allows the upper part of shell 2 to temporarily widen so as to facilitate the insertion of the foot of the user into liner 7.

In other words, the protective tongue 8 is substantially L-shaped and extends grazing to shell 2 in the area immediately above the instep of the foot and the tibia-astragalus junction of the ankle, and then ascends along the leg up to reach and insert below the cuff 5, so as to cover the lower section of the tibia.

Again with reference to FIG. 1, ski boot 1 also comprises one or more manually-operated, mechanical ski-boot closing devices 9 which are structured so as to selectively close/tighten shell 2 and cuff 5 so as to immobilize the user's leg inside boot 1, or better, liner 7.

In the example shown, in particular, the mechanical ski-boot closing devices 9 preferably, though not necessarily, consist of a series of lever closing buckles 9 which are arranged crosswise on shell 2 and/or on cuff 5 and/or on protective tongue 8, substantially astride the longitudinal gap of shell 2, so as to selectively close/tighten shell 2 and cuff 5 to stably immobilize the user's leg inside liner 7.

Ski boot 1 is preferably also provided with a manually-operated cuff locking device 10 which is structured so as to selectively:

-   -   rigidly lock cuff 5 to shell 2 so as to prevent′ any swinging         movement of cuff 5 on shell 2; or     -   totally release cuff 5 from shell 2 so as to allow cuff 5 to         freely swing both forwards and backwards about axis A.

The cuff locking device 10 and the lever closing buckles 9 are components already widely known in the sector of ski boots, and hence will not be further described.

With reference to FIGS. 1, 2 and 3, unlike currently known ski boots, the rigid shell 2 of boot 1 is internally provided with an oblong transversal stiffening plate 12 made of metal material, which is embedded in a rigid and non-removable manner within the lower wall 2 a of the shell, close to the tip of shell 2, in a substantially horizontal position and locally substantially perpendicular to the vertical centre plane M of the ski boot, and is also provided with two projecting overhangs or protrusions 12 a which jut out downwards while remaining on opposite sides of the centre plane M of the boot, up to emerge/crop out on the outer surface of the lower wall 2 a of the shell, i.e. outside shell 2, immediately above the sole 3, 3′ which is momentarily fixed to the lower wall 2 a of shell 2.

In other words, the transversal stiffening plate 12 is embedded within the lower wall 2 a of the shell, close to the tip of shell 2 and astride the vertical centre plane M of the ski boot, and the distal ends of the two projecting overhangs or protrusions 12 a of the transversal stiffening plate 12 emerge/crop out on the outer surface of the lower wall 2 a of the shell substantially at the metatarsal-phalangeal area of the foot.

In the example shown, in particular, the two projecting overhangs or protrusions 12 a of the transversal stiffening plate 12 are preferably arranged in a specular position on opposite sides of the centre plane M of the ski boot, and preferably, though not necessarily, are substantially cylindrical in shape or are substantially truncated-conical in shape, and tapered towards the distal end.

With reference to FIGS. 1, 2 and 3, the removable front sole 3 instead essentially consists of a rigid plate-shaped socle 13, which is made of plastic or composite material, and has the upper face 13 a shaped so as to be coupled and removably locked/engaged on the lower wall 2 a of shell 2, more or less at the tarsal-phalangeal area of the foot, and preferably also so as to partly cover the lower part of the ogival tip of shell 2; and of a slab 14 of elastomeric material and preferably with knobbed profile, which is fixed in a non-removable manner to the lower face 13 b of socle 13 so as to substantially cover the whole surface of the lower face 13 b of socle 13 thus forming a single block with socle 13. When the upper face 13 a of socle 13 is coupled to the lower wall 2 a of shell 2, the slab 14 of elastomeric material forms the front tread of ski boot 1.

The monolithic body formed by the socle 13 and the slab 14 of elastomeric material is also structured so as to be stably retained in abutment on the lower wall 2 a of shell 2 in a rigid and stable although easily removable manner, by means of a suitable number of anchoring screws 15, and is globally shaped/structured so as to meet, when the sole 3 is fixed to the lower wall 2 a of shell 2, the international standards in force for mountaineering ski boots (currently international standard ISO 9523 and the dimensional specifications required for coupling to Dynafit mountaineering ski-binding devices or the like).

In addition to the above description, with reference to FIGS. 1, 2 and 3, the removable front sole 3 also comprises an oblong transversal stiffening plate 16 made of metal material, which is rigidly embedded in a non-removable manner within socle 13, close to the front end of the socle 13 and preferably in a substantially horizontal position and locally substantially perpendicular to the vertical centre plane M of the boot, so as to be aligned below the stiffening plate 12 of shell 2 when sole 3 is fixed to the lower wall 2 a of the shell.

The stiffening plate 16 is also shaped so as to emerge/crop out from/on the surface of the upper face 13 a of socle 13 at two areas/portions 16 a which are located on opposite sides of the centre plane M of the boot, each aligned at the distal end of a corresponding projecting overhang 12 a of the stiffening plate 12, so that the stiffening plate 16 can rest directly on the two projecting overhangs or protrusions 12 a of the stiffening plate 12 of the shell when sole 3 is fixed to the lower wall 2 a of shell 2.

In other words, the stiffening plate 16 of sole 3 is embedded within socle 13, astride the vertical centre plane M of the boot, and is shaped/structured so as to emerge/crop out on the surface of the upper face 13 a of socle 13 at two areas/portions 16 a which are substantially located at the metatarsal-phalangeal area of the foot, on opposite sides of the centre plane M of the boot, so as to rest directly on the transversal stiffening plate 12 of shell 2.

Lastly, the stiffening plate 16 of the removable front sole 3 is structured so that the two axial ends 16 b of the same plate project from the lateral sides of socle 13, on opposite sides of the vertical centre plane M of the ski boot, and are shaped so as to be able to coupled to the clamp locking member of the toe-piece of a traditional mountaineering ski-binding device so as to allow the clamp locking member to grasp and retain/lock the stiffening plate 16, and what integral with the latter, with the modes envisaged by the international standards in force for mountaineering ski boots (currently international standard ISO 9523 and the dimensional specifications required for coupling to Dynafit mountaineering ski-binding devices or the like).

In other words, the shape of the two axial ends 16 b of the stiffening plate 16 and the position of the two axial ends 16 b of the stiffening plate 16 on the lateral sides of socle 13, are such so as to meet, when sole 3 is fixed to the lower wall 2 a of shell 2, the international standards in force for mountaineering ski boots (currently international standard ISO 9523 and the dimensional specifications required for coupling to Dynafit mountaineering ski-binding devices or the like).

Instead with regard to the anchoring screws 15, in the example shown the ski boot 1 is equipped with a series of anchoring pass-through screws 15 which are structured so as to engage the monolithic body formed by socle 13 and slab 14 of elastomeric material, in a pass-through manner, and to then be screwed into the lower wall 2 a of shell 2 so as to lock/retain socle 13 stably in abutment on the lower wall 2 a of shell 2.

More in detail, ski boot 1 comprises at least two main anchoring screws 15 which are arranged on opposite sides of the vertical centre plane M of the ski boot, and are structured so as to engage the monolithic body formed by socle 13 and slab 14 of elastomeric material in a pass-through manner at the two emerged areas/portions 16 a of the stiffening plate 16, so that the stem 15 a of each main anchoring screw 15 can engage the stiffening plate 16 of sole 3 in a pass-through manner at a respective emerged area/portion 16 a of the stiffening plate 16, and then can be directly screwed into the projecting protrusion or overhang 12 a below of the stiffening plate 12 of shell 2.

Thereby, each main anchoring screw 15 is capable of locking/retaining the stiffening plate 16 directly in abutment on the distal end of a respective projecting protrusion or overhang 12 a of the stiffening plate 12 of shell 2.

With reference to FIGS. 1 and 3, similarly to the removable front sole 3, the removable back heel 4 essentially consists of a rigid plate-shaped socle 18 which is made of plastic or composite material, and has the upper face 18 a shaped so as to be coupled and removably locked/engaged on the lower wall 2 a of shell 2, more or less at the heel of the user; and of a slab 19 of elastomeric material and preferably with knobbed profile, which is fixed in a non-removable manner to the lower face 18 b of socle 18 so as to at least partly cover the lower face 18 b of socle 18 thus forming a single block with the latter.

When the upper face 18 a of socle 18 is coupled to the lower wall 2 a of shell 2, the slab 18 of elastomeric material forms the back tread of ski boot 1.

In the example shown, in particular, socle 18 is fixed to the lower wall 2 a of shell 2, at the heel of the user, and is preferably, though not necessarily, provided with a flat projecting tailpiece which juts out towards the tip of shell 2 while remaining on the centre plane M of the boot, so as to cover the middle area of the lower wall 2 a of the shell which is located immediately below the arch of the foot of the user. This flat tailpiece of socle 18 is also preferably dimensioned so as to slide/insert below the removable front sole 3, so as to remain trapped between the lower wall 2 a of shell 2 and the front sole 3.

Similarly to the slab 14 of elastomeric material of the front sole 3, the slab 19 of elastomeric material is also preferably, though not necessarily, shaped so as to substantially cover the whole surface of the lower face 18 b of socle 18, flat tailpiece included, thus also sliding below the removable front sole 3.

Furthermore, similarly to the removable front sole 3, the monolithic body formed by socle 18 and slab 19 of elastomeric material is also structured so as to be stably retained in abutment on the lower wall 2 a of shell 2 in a rigid and stable although easily removable manner, by means of a convenient number of anchoring screws 20, and is overall shaped/structured so as to meet, when heel 4 is fixed to the lower wall 2 a of shell 2, the international standards in force for mountaineering ski boots (currently international standard ISO 9523 and the dimensional specifications required for coupling to Dynafit mountaineering ski-binding devices or the like).

In other words, ski boot 1 is also equipped with a second group of anchoring pass-through screws 20 which are structured so as to engage the monolithic body formed by socle 18 and slab 19 of elastomeric material, in a pass-through manner, and to then be screwed into the lower wall 2 a of shell 2 so as to lock/retain socle 18 stably in abutment on the lower wall 2 a of shell 2.

More in detail, the anchoring pass-through screws 20 are structured so as to engage the monolithic body formed by socle 18 and slab 19 of elastomeric material, in a pass-through manner, and to then be screwed into specific bushes 21 or other metal inserts fixed or embedded within the lower wall 2 a of shell 2 so as to lock/retain socle 18 stably in abutment on the lower wall 2 a of shell 2.

Again with reference to FIGS. 1 and 3, in addition, the removable back heel 4 also comprises a back stiffening plate 22 made of metal material, which is fixed in a rigid and stable although easily removable manner, to the back edge of the lower wall 2 a of shell 2 by means of at least one anchoring screw 23, so as to be arranged astride the centre plane M of the ski boot, immediately below the heel of the user. This stiffening plate 22 is also shaped/structured so as to be coupled to the locking member of the heel-piece of a traditional mountaineering ski-binding device, so as to allow the locking member to grasp and retain/lock the stiffening plate 22, and what is integral with the latter, with the modes envisaged by the international standards in force for mountaineering ski boots (currently international standard ISO 9523 and the dimensional specifications required for coupling to Dynafit mountaineering ski-binding devices or the like).

In other words, position and shape of the back stiffening plate 22 are such so as to meet, when the back stiffening plate 22 is fixed to the lower wall 2 a of shell 2, the international standards in force for mountaineering ski boots (currently international standard ISO 9523 and the dimensional specifications required for coupling to Dynafit mountaineering ski-binding devices or the like).

With reference to FIGS. 4 and 5, the second removable front sole 3′ instead consists essentially of a rigid plate-shaped socle 33 which is made of plastic or composite material, and has the upper face 33 a shaped so as to be coupled and removably locked/retained on the lower wall 2 a of shell 2, more or less at the tarsal-phalangeal area of the foot, and preferably also so as to partly cover the lower part of the ogival tip of shell 2; and of a slab 34 of plastic material, which has a sliding friction coefficient lower than the one of the elastomeric material used in the front sole 3, and is fixed in a non-removable manner to the lower face 33 b of socle 33 so as to substantially cover the whole surface of the lower face 33 b of socle 33 thus forming a single block with socle 33. The plastic material which forms slab 34 also has a rigidity which is preferably higher than that of the elastomeric polymeric material which forms the slab 14 of the removable front sole 3.

Similarly to slab 14 of the removable front sole 3, the slab 34 of plastic material also concurs to form the front tread of ski boot 1 when the removable front sole 3′ is fixed to the lower wall 2 a of shell 2.

In the example shown, in particular, slab 34 of sole 3′ is preferably made of nylon (polyamide), PEBAX (polyester-amide) or similar plastic polymers.

Alternatively, slab 34 of sole 3′ could also be made of elastomeric material, such as for example TPU (thermoplastic polyurethane).

The monolithic body formed by socle 33 and slab 34 of elastomeric material is also structured so as to be stably retained in abutment on the lower wall 2 a of shell 2 in a rigid and stable although easily removable manner, by means of a convenient number of anchoring screws, and is overall shaped/structured so as to meet, when sole 3′ is fixed to the lower wall 2 a of shell 2, the international standards in force for downhill ski boots (currently international standard ISO 5355).

In addition to what above, with reference to FIGS. 4 and 5, the second removable front sole 3′ also comprises an oblong transversal stiffening plate 36 made of metal material, which is rigidly embedded in a non-removable manner within socle 33, close to the front end of socle 33 and preferably in a substantially horizontal position and locally substantially perpendicular to the vertical centre plane M of the boot, so as to be aligned below the stiffening plate 12 of shell 2 when the sole 3′ is fixed to the lower wall 2 a of the shell.

The stiffening plate 36 of sole 3′ is also shaped so as to emerge/crop out from/on the surface of the upper face 33 a of socle 33 at two areas/portions 36 a which are located at opposite sides of the centre plane M of the boot, each aligned at the distal end of a corresponding projecting overhang 12 a of the stiffening plate 12, so that the stiffening plate 36 can rest directly on the two projecting overhangs or protrusions 12 a of the stiffening plate 12 of the shell when sole 3′ is fixed to the lower wall 2 a of shell 2.

In other words, the stiffening plate 36 of sole 3′ is embedded within socle 33, astride the vertical centre plane M of the boot, and is shaped/structured so as to emerge/crop out on the surface of the upper face 33 a of socle 33 at two areas/portions 16 a which are substantially located at the metatarsal-phalangeal area of the foot, on opposite sides of the centre plane M of the boot, so as to rest directly on the transversal stiffening plate 12 of shell 2.

Instead, as regards the locking of the removable front sole 3′ on the lower wall 2 a of the shell, the monolithic body formed by socle 33 and slab 34 of plastic material is structured so as to be stably retained in abutment on the lower wall 2 a of shell 2 in a rigid and stable although easily removable manner, by means of the same anchoring screws 15 which serve to lock the removable front sole 3′ on the lower wall 2 a of shell 2.

In other words, the anchoring pass-through screws 15 are structured so as to engage the monolithic body formed by socle 33 and slab 34 of elastomeric material, in a pass-through manner, and to then be screwed into the lower wall 2 a of shell 2 so as to lock/retain socle 33 stably in abutment on the lower wall 2 a of shell 2.

More in detail, also in this case, at least two main anchoring screws 15 are arranged in specular position on opposite sides of the centre plane M of the boot, and are structured so as to engage the monolithic body formed by socle 33 and slab 34 of plastic material in a pass-through manner at the two emerged areas/portions 36 a of the stiffening plate 36, so that the stem 15 a of each main anchoring screw 15 can engage the stiffening plate 36 of sole 3′ in a pass-through manner at a respective emerged area/portion 36 a of the stiffening plate 36, and then to be directly screwed into the projecting protrusion or overhang 12 a below of the stiffening plate 12 of shell 2.

Thereby, each main anchoring screw 15 is capable of locking/retaining the stiffening plate 36 directly in abutment on the distal end of a respective projecting protrusion or overhang 12 a of the stiffening plate 12 of shell 2.

With reference to FIG. 4, similarly to the second removable front sole 3′, the second removable back heel 4′ essentially consists of a rigid plate-shaped socle 38 which is made of plastic or composite material, and has the upper face 38 a shaped so as to be coupled and removably locked/engaged on the lower wall 2 a of shell 2, more or less at the heel of the user; and of a slab of plastic material, which has a sliding friction coefficient lower than the one of the elastomeric material used in the back heel 4, and is fixed in a non-removable manner to the lower face 38 b of socle 38 so as to substantially cover the whole surface of the lower face 38 b of socle 38 thus forming a single block with socle 38. The plastic material which forms slab 39 also has a rigidity which is preferably higher than that of the elastomeric polymeric material which forms the slab 18 of the removable back heel 4.

Similarly to slab 18 of the removable back heel 4, the slab 38 of plastic material also concurs to form the back tread of ski boot 1 when the removable back heel 4′ is fixed to the lower wall 2 a of shell 2.

In the example shown, in particular, slab 39 of heel 4′ is preferably made of nylon (polyamide), PEBAX (polyester-amide) or similar plastic polymers.

Alternatively, slab 39 of heel 4′ could also be made of elastomeric material, such as for example TPU (thermoplastic polyurethane).

In the example shown, in particular, socle 38 is removably fixed to the lower wall 2 a of shell 2, at the heel of the user, and is preferably, though not necessarily, equipped with a flat projecting tailpiece which juts out towards the tip of shell 2 while remaining on the centre plane M of the boot, so as to cover the middle area of the lower wall 2 a of the shell which is located immediately below the arch of the foot of the user. This flat tailpiece of socle 38 is also preferably dimensioned so as to slide/merge below the removable front sole 3′, so as to remain trapped between the lower wall 2 a of shell 2 and the front sole 3′.

Similarly to the slab 34 of elastomeric material of the front sole 3′, the slab 39 of elastomeric material is also preferably, though not necessarily, shaped so as to substantially cover the whole surface of the lower face 38 b of socle 38, flat appendix included, thus also sliding below the removable front sole 3′.

Furthermore, similarly to the removable front sole 3′, the monolithic body formed by socle 38 and by the slab of elastomeric material 39 is also structured so as to be stably retained in abutment on the lower wall 2 a of shell 2 in a rigid and stable although easily removable manner, by means of a convenient number of anchoring screws, and is overall shaped/structured so as to meet, when heel 4′ is fixed to the lower wall 2 a of shell 2, the international standards in force for downhill ski boots (currently international standard ISO 5355).

More in detail, in the example shown, the monolithic body formed by socle 38 and slab 39 made of plastic material is preferably structured so as to be stably retained in abutment on the lower wall 2 a of shell 2 in a rigid and stable although easily removable manner, by means of the anchoring screws 20 and 23 which serve to lock the back heel 4 on the lower wall 2 a of the shell.

The general operation of ski boot 1 is easily inferable from the above description, and therefore does not require further explanations.

Instead with regard to the coupling of the removable front soles 3 and 3′, experiments have shown that the direct contact between the metal stiffening plate 12 inside shell 2 and, selectively and alternatively, the metal stiffening plate 16 embedded within the removable front sole 3, or the metal stiffening plate 36 embedded within the removable front sole 3′, gives the front part of ski boot 1 higher structural rigidity than the standard one of current ski boots with removable sole and heel.

This localized increase of the structural rigidity of the ski boot makes the dynamic behaviour and reactivity of ski boot 1 practically identical to those encountered in ski boots with sole and heel made in a single piece with the shell.

There are several advantages resulting from the particular structure of shell 2 and of the two different removable front soles 3 and 3′. Ski boot 1 may be employed in complete safety, both in downhill skiing and in mountaineering, thus ensuring dynamic behaviour and reactivity which are practically identical to those of ski boots with sole and heel made in a single piece with the shell.

Lastly, it is apparent that modifications and variants may be made to the above-described ski boot 1 without departing from the scope of the present invention.

For example, rather than being equipped with two separate projecting overhangs or protrusions 12 a which jut out downwards up to emerge/crop out on the outer surface of the lower wall 2 a of the shell, in a different embodiment the transversal stiffening plate 12 of shell 2 could be shaped/structured so that the middle inner portion thereof can emerge/crop out on the outer surface of the lower wall 2 s of the shell, astride the vertical centre plane M of the boot, and substantially at the metatarsal-phalangeal area of the foot. Obviously, the dimensions of this middle portion are to be sufficient to ensure stable resting of the removable front soles 3 and 3′ on the transversal stiffening plate 16, 36.

Also in this case, at least one of the main anchoring screws 15 is adapted to lock/retain any one of the removable front soles 3 and 3′ in abutment on the lower wall 2 a of the shell, by engaging the monolithic body formed by socle 13 or 33 and slab of elastomeric material 14 or 34, and the transversal stiffening plate 16, 36 embedded within socle 13 or 33, in a pass-through manner, to then be screwed directly into the beneath located emerged central portion of the stiffening plate 12 of shell 2. 

1. Ski boot comprising a rigid shell which is made of plastic or composite material and is shaped so as to accommodate the foot of the user, and at least a first and a second removable front sole which, alternatively to one another, are adapted to be fixed in a rigid and stable although easily removable manner on the lower wall of the shell substantially at the tarsal-phalangeal area of the foot; said first and said second removable front sole being structured for being fixed on the back of the ski by means of a ski-binding device; the ski boot being characterised in that the shell is provided with a first transversal stiffening plate made of metal material which is embedded within the lower wall of the shell, close to the tip of the shell, and is structured/shaped so as to partially emerge/crop out on the outer surface of the lower wall of the shell substantially at the metatarsal-phalangeal area of the foot; and in that both the first and the second removable front sole comprise: an upper plate-shaped socle which has the upper face shaped so as to removably couple with the lower wall of the shell substantially at the tarsal-phalangeal area of the foot, and a second transversal stiffening plate made of metal material which, in turn, is embedded within the upper plate-shaped socle close to the front end of the socle, so as to be aligned below the transversal stiffening plate of the shell, and is furthermore shaped so as to emerge/crop out on the surface of the upper face of the socle substantially at the metatarsal-phalangeal area of the foot, so as to rest directly on the transversal stiffening plate of the shell.
 2. Ski boot according to claim 1, characterised in that the first removable front sole also comprises a slab of elastomeric material which is fixed on the lower face of the upper plate-shaped socle so as to form a single block with the socle; said single block being overall shaped/structured so as to meet the standards for mountaineering ski boots.
 3. Ski boot according to claim 2, characterised in that the slab of elastomeric material has a knobbed profile.
 4. Ski boot according to claim 1, characterised in that also the second removable front sole comprises a slab of plastic or elastomeric material which is fixed on the lower face of the upper plate-shaped socle so as to form a single block with the socle; said single block being overall shaped/structured so as to meet the standards for downhill ski boots.
 5. Ski boot according to claim 4, characterised in that the slab of plastic material is made of a polymeric material which has a sliding friction coefficient lower than that of the elastomeric material of the slab of elastomeric material of the first removable front sole.
 6. Ski boot according to claim 1, characterised by also comprising at least one first anchoring screw which is adapted to lock/retain the upper plate-shaped socle of the first or second removable front sole in abutment on the lower wall of the shell.
 7. Ski boot according to claim 6, characterised in that said first anchoring screw is adapted so as to engage in pass-through manner the upper plate-shaped socle of the first or second removable front sole and the transversal stiffening plate embedded in the upper plate-shaped socle, and then to screw directly in the emerged portion of the transversal stiffening plate of the shell.
 8. Ski boot according to claim 1, characterised in that the transversal stiffening plate of the shell is provided with two projecting overhangs or protrusions which jut out while remaining on opposite sides of the vertical centre plane of the boot (M), up to emerge/crop out on the outer surface of the lower wall of the shell, substantially at the metatarsal-phalangeal area of the foot.
 9. Ski boot according to claim 8, characterised in that the two projecting overhangs or protrusions of the shell transversal stiffening plate are arranged in a specular position on opposite sides of the vertical centre plane of the ski boot (M).
 10. Ski boot according to claim 8, characterised in that the transversal stiffening plate of the first and of the second removable front sole is shaped so as to emerge/crop out from/on the surface of the upper face of the upper plate-shaped socle at two areas/portions which are located on opposite sides of the vertical centre plane (M) of the ski boot, each aligned at the distal end of a corresponding projecting overhang or protrusion of the shell transversal stiffening plate, to abut on the distal end of said projecting overhang or protrusion.
 11. Ski boot according to claim 10, characterised by comprising at least two first anchoring screws which are arranged on opposite sides of the vertical centre plane (M) of the ski boot, and each of said first anchoring screws is structured so as to engage in pass-through manner the upper plate-shaped socle at a corresponding emerged area/portion of the transversal stiffening plate of the first or second removable front sole, and then directly screw into the underlying projecting overhang or protrusion of the transversal stiffening plate of the shell.
 12. Ski boot according to claim 1, characterised by also comprising at least a first and a second removable back heel which, alternatively to one another, are adapted to be fixed in a rigid and stable although easily removable manner on the lower wall of the shell substantially at the heel of the foot.
 13. Ski boot according to claim 12, characterised in that both the first and the second removable back heel comprise an upper plate-shaped socle which has the upper face shaped so as to be removably coupled with the lower wall of the shell substantially at the heel of the foot.
 14. Ski boot according to claim 13, characterised in that the first removable back heel also comprises a slab of elastomeric material which is fixed on the lower face of the upper plate-shaped socle so as to form a single block with the socle; said single block being overall shaped/structured so as to meet the standards for mountaineering ski boots.
 15. Ski boot according to claim 13, characterised in that the second removable back heel also comprises a slab of plastic or elastomeric material which is fixed on the lower face of the upper plate-shaped socle so as to form a single block with the socle; said single block being overall shaped/structured so as to meet the standards for downhill ski boots.
 16. Ski boot according to claim 1, characterised by also comprising a rigid cuff which is shaped so as to enclose the ankle of the user and is hinged on the shell so as to rotate about an axis (A) substantially perpendicular to the vertical centre plane (M) of the ski boot. 